an electric circuit that can be connected to other circuits only at certain specially provided terminals, called poles. The representation of individual parts of a complex electric circuit as a multiterminal network often facilitates calculation, since the method requires determination only of the voltages between the poles and the currents in the poles, rather than of the currents and potentials for all components of a circuit, the number of which may be large. This is entirely sufficient for the solution of many practical problems.
A multiterminal network is called active if it contains independent power sources whose effects are not mutually compensated. If all poles of such a multiterminal network are opened, potential differences will exist among all or several poles as a result of the existence of internal power sources. Multiterminal networks not containing any independent power sources are called passive.
Multiterminal networks are classified as linear or nonlinear. In linear networks, linear relationships exist between current and voltage, and the superposition principle can be used for computations; in nonlinear multiterminal networks the principle cannot be used. Multiterminal networks are called reversible or nonreversible based on their conformance or nonconformance to the reciprocity theorem. According to the number of poles, multiterminal networks are called three-terminal networks, four-terminal networks, and so on.